Retroactive inhibition
The Interference theory of memory states that people forget not because memories are actually lost from storage, but because other information gets in the way of what people want to remember. Retroactive inhibition or retroactive interference is one aspect of this theory and occurs when the material learned later disrupts retrieval of information learned earlier, so old information overlaps with new information. Iconic research Modified (free) recall Briggs (1954) study modeled McGeoch’s work on interference by setting the stage for a classic design of retroactive interference. In his study participants were asked to learn 12 paired associates to a criterion of 100%. To ensure parsimony, these pairs can be labeled as A1-B1-, A2-B2-…Ai-Bi (also called AB/AC paradigm). Briggs used a “modified free recall” technique by asking participants to recall an item when cued with Bi. Over multiple anticipation trials, participants learned Bi items through the prompt of Bi items. After perfecting Ai- Bi learning, participants were given a new list of paired associates to learn; however Bi items were replaced with Ci items (now given a list of A1-C1-, A2-C2-…Ai-Ci). As the learning of Ai-Ci pairs increased, the learning of Ai-Bi pairs decreased. Eventually recalling the Ci items exceeded the recall of the Bi items, representing the phenomenon of retroactive interference. A significant part of Briggs (1954) study was that once participants were tested after a delay of 24 hours the Bi responses spontaneously recovered and exceeded the recall of the Ci items. Briggs explained the spontaneous recovery illustration as an account of Ai-Bi items competing with Ai-Ci items or, as McGeoch would define it: “a resultant of momentary dominance” Briggs, G. E. (1954). Acquisition, extinction, and recovery functions in retroactive inhibition. Journal of Experimental Psychology, 47, 285-293 Modified modified free recall J.M. Barnes and B.J. Underwood (1959) expanded Briggs (1954) study by implementing a similar procedure. The main difference in this study, however, was that unlike Briggs (1954) “modified free recall” (MFR) task where participants gave one item responses, Barnes and Underwood asked participants to give both List 1 and List 2 responses to each cued recall task. Participants’ ability to recall both items was termed “modified modified free recall” (MMFR) technique. Equivocally to Briggs (1954) results, RI occurred when Ci recalled responses gradually came to exceed Bi responses. Barnes and Underwood argued that because there was “unlimited recall time” to produce multiple item responses, the fact that Ai-Ci responses still trumped Ai-Bi responses represented an account of unlearning.Barnes, J. M> & Underwood, B. J. (1959). Fate of first-list associations in transfer theory. Journal of Experimental Psychology, 58, 97-105 Theories The phenomenon of retroactive interference is highly significant in the study of memory as it has sparked a historical and ongoing debate in regards to whether the process of forgetting is due to the interference of other competing stimuli, or rather the unlearning of the forgotten material. The important conclusion one may gain from RI is that “forgetting is not simply a failure or weakness of the memory system” (Bjork, 1992), but rather an integral part of our stored knowledge repertoire. Although modern cognitive researchers continue to debate the actual causes of forgetting (e.g., competition vs. unlearning), retroactive interference implies a general understanding that additional underlying processes play a role in memory. Competition A standard explanation for the cause of RI is Competition. New associations compete with older associations and the more recent association would win out making it impossible to remember earlier associations. Spontaneous Recovery in MFR supports the claim of competition since after a rest period participants spontaneously remembered original pair associations that they were not able to remember right after the second test. Associative Unlearning The Associative unlearning Hypothesis explains RI by saying that new associations replace the old associations in memory causing the participant to forget the initial associations. Barnes and Underwood argued that Ai-Ci responses still outnumbering Ai-Bi responses after the delay period supports the Associative Unlearning Hypothesis over Competition. Brain structures Retroactive Interference has been localized to the left anterior ventral prefrontal cortex by magnetoencephalography (MEG) studies investigating Retroactive Interference and working memory in elderly adults.Solesio, E., Lorenzo-López, L., Campo, P., López-Frutos, J.M., Ruiz-Vargas, J.M., & Maestú, F. (2009). Retroactive interference in normal aging: A magnetoencephalography study. Neuroscience Letters, 456, 85-88. The study found that adults 55–67 years of age showed less magnetic activity in their prefrontal cortices than the control group. Executive control mechanisms are located in the frontal cortex and deficits in working memory show changes in the functioning of this brain area. Research Pitch perception Retroactive Interference has also been investigated using pitch perception as the learning medium.Massaro, D.W. (1970). Retroactive Interference in Short Term Memory for Pitch. Journal of Experimental Psychology, 83, 32-39. The researcher found that the presentation of subsequent stimuli in succession causes a decrease in recalled accuracy. Massaro found that the presentation of successive auditory tones, confused perceptual short term memory, causing Retroactive Interference as the new tone inhibits the retrieval of previously heard tones. Motor movement Wohldmann, Healey and Bourne found that Retroactive Interference also affects retention of motor movements. Researchers found that retroactive interference affects the performance of old motor movements when newly acquired motor movements are practiced. Physical practice of newly executed motor movements decreased the retention and recall of previously learnt movements. Despite the retroactive interference noted by Wohldmann et al., researchers noted that mental practice decreased the amount of retroactive interference, suggesting that mental practice is more flexible and durable over time. This study of the superiority effect of physical practice is similar to the Word Superiority Effect made famous by Cattell.Cattell, J. M. (1886). "The time it takes to see and name objects". Mind, 11, 63-65 Word tasks Retroactive Interference increases when the items are similar, therefore increasing association between them as shown by spreading activation.Barnes, J.M. & Underwood, B.J. (1959). Fate of first list association in transfer theory. Journal of Experimental Psychology, 58, 97-105. Barnes and Underwood found that when participants in the experimental condition were presented with two similar word lists, the recollection of the first word list decreased with the presentation of the second word list. This finding contrasts the control condition as they had little Retroactive Inference when asked to recall the first word list after a period of unrelated activity. See also * Forgetting * Latent inhibition * Proactive interference * Output interference * Prepulse inhibition References & Bibliography Key texts Books Papers Additional material Books Papers *Google Scholar External links Category:Memory Category:Memory Category:Memory theory Category:Interference theory Category:Psychological theories